The formula is not an official law, but rather an agreement amongst the rather large coalition of four parties. After the 2003 general elections, the formula was modified, giving two seats to the SVP/UDC at the expense of the Christian Democrats. This was because the Swiss People's Party received 29% of the votes during the election of the parliament making it Switzerland's largest party by votes.

After the election of Eveline Widmer-Schlumpf to the federal council in Autumn 2007, she was expelled from the SVP/UDC, because she took the seat of Christoph Blocher, the unofficial leader of the SVP. The SVP's other councilor, Samuel Schmid followed her, as he, too, was no longer supported by his own party. They led the establishment of the new Conservative Democratic Party of Switzerland (BDP/PBD). Due to this change, the two seats from the SVP/UDC now belonged to the PDB, although it had only a handful of seats in the parliament.[2]

On 12 November 2008, Schmid resigned from his post as Defense minister and was replaced in a vote that took place on 10 December 2008 by Ueli Maurer from the SVP/UDC, giving the party back one of its two magic formula seats.